This invention relates generally to wearable electronic devices, such as computers and audio-video devices, and more specifically to a system and method for cooling such electronic devices when worn on the body of a user.
In today""s society, electronic devices are becoming more indispensable for everyday tasks. For example, personal computers have become more popular in everyday life, and therefore are often necessary in the daily activities of a computer user. As such, many people desire almost constant access to their computers and other electronic devices. As technology and communications advance, and as more goods and services are available through the use of a computer, such as over the Internet, the desire for constant access will continue to increase among computer users. This same rationale applies to electronic devices such as audio and video devices which might be used for communications.
Conventionally, computers and other electronic devices utilized by individuals and businesses are stand-alone devices which are generally permanently placed on a desk top, table top, floor, or other support surface. While they may be readily moved from place to place, they are not meant to be constantly carried around by the user. To address the need for portability, many electronic devices are portable, and portable computers are available which are carried by the user, generally in a specially made suitcase or bag. Existing portable computers and other similar devices continue to decrease in size and weight, but are still designed to be carried like luggage in a separate bag or other container and are then subsequently used by placing them on an available support surface, such as a desk top.
Recently, wearable computers and wearable audio and video systems have become available. Wearable electronic devices, such as a wearable personal computer, are meant to be used while being worn on the body of the user. Such wearable devices are usually carried on the body without having to be hand-carried like luggage and are more likely to be used while being worn, rather than being taken off and placed on a support surface. This arrangement provides the user with greater mobility, convenience, and flexibility in the use of the device.
Wearable electronic devices have internal electronic components which generate heat during their operation and the operation of the computer. In particular, electronic devices using high performance processors, such as Intel Pentium-class processors, generate a substantial amount of heat. As a result, the temperature of the processor component and the overall device may exceed operating specifications. Consequently, the electronic components of such devices, and particularly processor components, must be cooled in some way for proper operation. In addition to ensuring proper operation of internal electronic components, wearable computers also must be cooled sufficiently to ensure the comfort of the wearer. Unlike desktop or portable computers, wearable computers will generally be in contact with the user""s body and possibly their bare skin while being used.
In existing devices, such as desktop and laptop computers, an internal air moving device, such as an internal fan, may be utilized to direct cooling air over the heat-generating components to cool those components. Additionally, large heat sinks and heat pipes might be utilized. However, existing cooling systems for computers and other devices, while functional for conventional desktop or portable computers, have certain drawbacks with respect to their incorporation into a wearable device.
Cooling components, such as large heat sinks, heat pipes, fans and the like, are generally too large and cumbersome for use in wearable devices. Furthermore, some cooling devices consume too much power to be practical for a wearable device, which will generally be powered from a portable source, such as a battery.
Still further, internal air moving devices, like fans, require relatively large airflow openings in the body or housing of the computer for feeding and exhausting air to and from the internal volume of the computer to cool the electronic components. Such large air flow openings are suitable for existing desktop and portable computers, because those devices will primarily be used indoors and thus are not significantly exposed to outside environmental elements, such as water and dirt. However, wearable devices and computers are worn by a user and are therefore exposed to the environmental elements to which the user is exposed. Consequently, a wearable device will be exposed to water, dirt, and other contaminant elements. Large airflow openings and fans which draw air through the openings also allow the water, dirt, and other contaminating elements into the internal volume of the computer and expose the electronic components to such contaminating elements.
Some versions of wearable computers have been cooled without an internal fan. However, those designs still use relatively large airflow openings. Furthermore, the convective heat transfer between the air surrounding the components and the computer body is very inefficient. This inefficiency results in higher internal component temperatures and less reliable operation.
Therefore, it is an objective to improve the design and operation of electronic devices, such as computers, and more specifically to improve the cooling characteristics of a wearable electronic device.
It is another objective of the invention to cool a wearable device without cumbersome and power-consuming components.
It is another objective to reduce and eliminate exposure of the electronic components of a wearable device to environmental elements which may adversely affect the operation of the device.
It is still another objective to provide a computer for a user to wear without exposing the user to uncomfortably hot surfaces.
These objectives and other objectives of the present invention will become more readily apparent from the further description of the invention below.
The above objectives and other objectives are addressed by the present invention which comprises a system and method for cooling a wearable electronic device which has a heat-generating component, such as a wearable computer, with a microprocessor component.
The system comprises utilizing a surface which is thermally coupled to the heat-generating component, and is heated by the component. A fabric material is positioned proximate to the surface, and the fabric material includes a plurality of fibers which have heat conductive properties. For example, metallic fibers such as aluminum, copper, and/or iron fibers might be utilized in the fabric material and woven through the fabric material. The fabric material is configured for engaging the heated surface such that the heat conductive fibers of the fabric material are operable for conducting heat away from the surface to cool the component and the overall electronic device.
In one embodiment of the invention, the heated surface, which is thermally coupled to the component, has a three-dimensional topography. The fabric material engages the three-dimensional topography and engages the heated surface so that the heat conductive fibers weave through the three-dimensional topography of the surface. For example, the fabric material may also have a three-dimensional topography which generally follows at least a portion of the topography of the surface.
In another embodiment of the invention, the fabric material may be pressed against the heated surface for causing conductive contact between the heat conductive fibers and the surface. Alternatively, the heat conductive fibers and the surface may have magnetic properties, such that the surface and the heat conductive fibers are magnetically attracted to each other for good conductive contact. In one example, at least one of the surface and the fibers may be ferromagnetic, while the other of the surface and fibers is permanently magnetized. Alternatively, the surface and/or fibers may be impregnated with magnetic particles.
In still another embodiment, a press device is positioned on one side of the fabric material generally opposite the heated surface. The press device and surface have magnetic properties such that the press device and surface are magnetically attracted to each other to press the fibers into contact with the heated surface to conduct heat away from the surface. For example, at least one of the surface and the press device may be ferromagnetic while the other of the surface and press device is generally magnetized for attraction to the ferromagnetic material.
The magnetic properties of the heat conductive fibers and the heated component surface or press device may also provide alignment between the fabric material and the heat-generating component. For example, in one embodiment of the invention, the fabric material is incorporated into a garment or pack utilized or worn by a person who would be wearing an electronic device, such as a wearable computer. For proper operation of the cooling system of the invention, the fabric material and heat conductive fibers must be aligned with and contact the heated surface in order to conduct heat away from the surface and then convectively exchange heat with the ambient atmosphere. Magnetic attraction between the fabric material and the heated surface or between the surface and a press device coupled to the fabric material will ensure such alignment.
In accordance with another aspect of the present invention, the heat conductive fibers are positioned in the fabric material to lie adjacent an inner side of the fabric material proximate to the heated surface for a conductive transfer of heat from the surface, and to lie adjacent an outer side of the fabric material away from the heated surface to facilitate the convective transfer of the heat to the surrounding air and ambient atmosphere. Furthermore, in that way, heat is kept away from the user""s skin. This may be a particularly desirable property when the fabric material is incorporated into a garment, such as a shirt or pants worn by the user.
Other features and benefits of the invention will become more readily apparent from the Detailed Description of the invention below.